UMA stats for stylus usage

chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
index 61a76aaa4b121608682bea2e502b59921b1f6dfe..934c27bf23dfc875611c67c8c0f460a81c64341b 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
@@ -31,6 +31,12 @@ class Profile;
 class AppWindowLauncherController;
 class TabContents;
 
+#if defined(OS_CHROMEOS)
+namespace chromeos {
+class StylusMetricsRecorder;
+}
+#endif
+
 namespace ash {
 class ShelfModel;
 namespace launcher {
@@ -368,6 +374,11 @@ class ChromeLauncherControllerImpl
   typedef std::map<std::string, RunningAppListIds> RunningAppListIdMap;
   RunningAppListIdMap last_used_running_application_order_;
 
+#if defined(OS_CHROMEOS)
+  // Record stylus metrics for down event.
+  std::unique_ptr<chromeos::StylusMetricsRecorder> stylus_metrics_recorder_;
+#endif
+
   base::WeakPtrFactory<ChromeLauncherControllerImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeLauncherControllerImpl);